How Paychecks Are Calculated in the U.S.

Start with gross earnings

For salaried employees, payroll generally divides annual salary by the number of pay periods. Hourly employees are paid for recorded regular hours plus eligible overtime, shift differentials, tips, commissions, or bonuses. Weekly payroll normally creates 52 checks, biweekly 26, semimonthly 24, and monthly 12. A biweekly deposit should not be compared directly with a semimonthly deposit.

Convert gross pay into taxable wages

Gross pay and taxable wages can differ. Traditional 401(k), qualifying health coverage, HSA, and FSA deductions may reduce wages for one tax without reducing them for another. Payroll therefore maintains separate federal income-tax, Social Security, Medicare, state, and sometimes local wage bases. Applying one combined percentage to gross pay misses these differences.

Calculate federal income-tax withholding

Federal withholding is a prepayment based on taxable wages, pay frequency, and Form W-4. The system is progressive: only income inside each bracket is taxed at that bracket rate. Your highest marginal rate is not the percentage applied to every dollar, and withholding is not necessarily the same as final tax liability.

Calculate Social Security and Medicare

FICA is separate from federal income tax. Social Security applies only until annual Social Security wages reach the wage base. Medicare generally continues without that cap, and Additional Medicare withholding can begin above an employer threshold. A traditional 401(k) may reduce federal taxable wages while leaving FICA wages unchanged.

Apply state, local, and other deductions

A state may use progressive brackets, a flat rate, or no broad wage income tax. Cities, counties, disability programs, and paid-leave programs can add deductions. Payroll then subtracts insurance, retirement savings, garnishments, union dues, or other authorized items. These reduce the deposit but are not all taxes.

Reconcile the pay stub

Review gross earnings, hours, taxable wages, each tax line, benefit deductions, year-to-date totals, and net pay. Compare year-to-date figures instead of judging one unusual overtime or bonus check. Report an incorrect pay rate, state, or benefit election promptly because the same error can repeat.

Worked paycheck example

An employee earns $3,000 biweekly and contributes $150 to a traditional 401(k). Gross pay is $3,000, but modeled federal taxable wages may be lower. Social Security and Medicare can still use a different wage base. After federal, FICA, state tax, and the retirement deduction, the remaining amount is net pay. Health insurance or local tax can reduce the actual deposit further.

Common mistakes to avoid

• Using one flat percentage for every deduction
• Ignoring whether pay is biweekly or semimonthly
• Calling insurance or retirement savings a tax
• Forgetting local taxes and state payroll programs
• Comparing an unusual bonus check with an ordinary paycheck

Frequently asked questions